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Biomedical subjects

M Shimoda

Publications and source records attributed to M Shimoda.

At least 199 records · Page 11Linked to original sources
PubMed1984

Increased calcium uptake in the red cells of unsplenectomized patients with hereditary spherocytosis: significant contribution of reticulocytosis.

The presence of abnormal calcium (Ca) metabolism in the red cells of hereditary spherocytosis (HS) patients has long been in dispute. Thus, to clarify the discrepancies of experimental results published previously, Ca metabolism in the red cells was investigated in 12 unsplenectomized and 6 splenectomized HS patients. A marked increase of Ca uptake was observed in the ATP-depleted red cells of the unsplenectomized HS patients. The increased red cell Ca uptake was normalized after splenectomy in the same HS patients. The extent of increased Ca uptake was well correlated to the degree of reticulocytosis (p less than 0.001). The observation was confirmed by the fractionation studies of the HS red cells. Ca uptake was not increased in the spherocyte-rich bottom fraction, if reticulocytosis was not present. No significant difference was observed in red cell calcium content between normal and HS patients, neither unsplenectomized nor splenectomized.

Adenosine Triphosphate↗
PubMed1984

Pharmacokinetic analysis of plasma concentration and urinary excretion of sulphamonomethoxine and its metabolite in Goettingen minipigs.

The plasma concentration and renal excretion after a bolus intravenous injection of a low (10 mg/kg) or high (100 mg/kg) dose of sulphamonomethoxine (SMM) were studied in five Goettingen minipigs. The time data of plasma concentration after a low dose decreased rapidly and appeared to be linear on semilog graph paper. On the other hand, a decrease in the plasma concentration after a high dose was slow at first, gradually accelerated, then became rapid, showing that SMM disposition after a high dose (100 mg/kg) seemed to be non-linear with capacity-limited elimination. A large amount of the acetyl derivative of SMM (AcSMM), which was determined to be the main excretory product of SMM in urine, was detected in the plasma after SMM injection. As the ratios of the area under plasma concentration-time curve of AcSMM to that of SMM were not significantly different at either dose, the acetylation of SMM may be unsaturable by injection of 100 mg/kg of SMM. Immediately after the injection of a low dose, a rapid hyperbolic increase of the fraction of the cumulative amount of the excretory products in urine was observed. On the other hand, the fraction curve at the high dose rose slowly at first, then rapidly and hyperbolically. These results suggested that the non-linear drug disposition after a high dose (100 mg/kg) of SMM in pigs may be the result of a limited capacity for renal excretion of SMM and excretory products, especially the acetyl derivative.

Animals↗
PubMed1981

Three compartment model for pyrimethamine disposition in the pig.

Plasma concentration and urine excretion of pyrimethamine (Py) after intravenous (i.v.) administration (10 mg/kg) were determined in four pigs, using NP-FID gas chromatography. A three-compartment model system adequately fitted the observed plasma data. Py may undergo an extensive extravascular distribution, because of the ratio of total volume of distribution to volume of the central compartment was extremely large (about 10). From the calculation of theoretical distribution, only 30% of the dose appears to remain in the central compartment 15 min after administration. Within 2 h of administration the proportion of drug within the two identified peripheral compartments exceeded the proportion remaining in the central compartment. Calculation of cumulative drug excretion showed that up to 90% of an administered dose is excreted within 24 h of administration, although only about 3% of the dose could be detected in urine in an unchanged form during the 24 h period.

Animals↗
PubMed1981

Serial endoscopic observation of swine gastroesophageal ulceration induced by injection of a histamine-oil-beeswax mixture.

The gastroesophageal (GE) area of swine was endoscopically observed before and after injection of a histamine-oil-beeswax mixture (5 mg of histamine/kg of body weight). The swine were anesthetized with halothane, and a rigid endoscope was inserted through a gastric cannula placed in the proximal greater curvature of the stomach. Observation was simple and the procedure lasted less than 10 minutes, without adverse reactions. In 4 swine with normal GE areas, hemorrhage was found at postmedication hour (PMH) 3 and ulcerative changes were seen at PMH 9 to 12. A more rapid pathologic change of the GE area was found in 2 animals with hyper- or parakeratotic changes before medication. Abnormalities were found up to PMH 9 in the GE area of 2 animals in which the stomach cannula was opened to allow the escape of gastric juice.

Animals↗